This invention relates to the art of tilt mountings for supporting equipment such as cameras, antennas, laser beam generators, spot lights, or the like equipment, which must be selectively tilted during operation, and more particularly to a tilt mounting which permits the supported equipment to be tilted while maintaining its center of gravity in a substantially horizontal plane.
A variety of equipment supporting mounts have been evolved over the years, serving to support the equipment in a pre-selected position. Such mountings provide for "panning", that is rotation of the equipment in a horizontal plane; or "tilting" permitting the equipment to be swung in a vertical plane. Such mounts are clamped on vertical posts supported on tripods, dollies, or the like, and loosening of the clamp permits ready panning. The panning movement presents few problems of balance, since the center of gravity of the equipment remains relatively fixed with respect to the pivot axis.
However, tilting presents a problem, in that the weight of the camera, where it is offset with respect to the axis of tilting, as is usually the case, creates a turning moment, making it difficult to achieve the desired smooth and easy tilting action.
It has been found that maintaining the center of gravity of the equipment at a relatively constant height as the equipment is tilted, serves to substantially minimize imbalance, and ease of tilting is substantially facilitated.
To this end, attempts have been made in the past to provide tilt mountings which serve to maintain the center of gravity of the supported equipment at a substantially constant height. In British Patent 807,555 of Jan. 14, 1959, a tilt mounting is disclosed in which vertical guide bars are pivotally connected to the tiltable support member at its tilt axis, and cam plates are secured to the tiltable support member, so that upon tilting of the support member, the cam plates will act to raise the tiltable support member and its guide bars, thus simultaneously tilting the equipment and raising its center of gravity. The equipment disclosed by this British patent is relatively complex, requiring very precise positioning of the guide bars and continuous lubrication and maintenance of the guide bar bearings.
Mooney in U.S. Pat. No. 3,545,710, has attempted to eliminate some of the problems of British Patent 807,555, by eliminating the guide bars and bearings of the British patent. Mooney, however, has provided a mechanism in which a link is provided having ears pivotally connected to the base support, and another portion of the link pivotally connected to the tilt table. A relatively complex cam surface is formed at the pivot connection between the tilt table and the link, so that upon tilting of the tilt table, the cam surface will urge the table and its equipment to be raised to effect a raising of the center of gravity of the tilting equipment. The relatively complex cam surface and link structure result in a relatively expensive structure with the cam subject to jamming in its movement along the cam surface.